Initial impact and cost of a nationwide population screening campaign for diabetes in Brazil : a follow up study

Abstract

Background: In 2001 Brazilian citizens aged 40 or older were invited to participate in a nationwide population screening program for diabetes. Capillary glucose screening tests and procedures for diagnostic confirmation were offered through the national healthcare system, diagnostic priority being given according to the severity of screening results. The objective of this study is to evaluate the initial impact of the program. Methods: Positive testing was defined by a fasting capillary glucose ≥ 100 mg/dL or casual glucose ≥ 140 mg/dL. All test results were tabulated locally and aggregate data by gender and clinical categories were sent to the Ministry of Health. To analyze individual characteristics of screening tests performed, a stratified random sample of 90,106 tests was drawn. To describe the actions taken for positive screenees, a random sub-sample of 4,906 positive screenees was actively followed up through home interviews. Main outcome measures considered were the number of diabetes cases diagnosed and cost per case detected and incorporated into healthcare. Results: Of 22,069,905 screening tests performed, we estimate that 3,417,106 (95% CI 3.1 – 3.7 million) were positive and that 346,168 (290,454 – 401,852) new cases were diagnosed (10.1% of positives), 319,157 (92.2%) of these being incorporated into healthcare. The number of screening tests needed to detect one case of diabetes was 64. As many cases of untreated but previously known diabetes were also linked to healthcare providers during the Campaign, the estimated number needed screen to incorporate one case into the healthcare system was 58. Total screening and diagnostic costs were US$ 26.19 million, the cost per diabetes case diagnosed being US$ 76. Results were especially sensitive to proportion of individuals returning for diagnostic confirmation. Conclusion: This nationwide population-based screening program, conducted through primary healthcare services, demonstrates the feasibility, within the context of an organized national healthcare system, of screening campaigns for chronic diseases. Although overall costs were significant, cost per new case diagnosed was lower than previously reported. However, cost-effectiveness analysis based on more clinically significant outcomes needs to be conducted before this screening approach can be recommended in other settings.